Then, Patterson addressed the public’s concern about the unusual taste and odor of the water that has been experienced off and on during the past couple of months.

He reminded the council there was a severe drought last summer, and by March, West Lake was 63.5 inches below the spillway.

By April, the rains came, and continued to come for the next few months.

“Part of the problem with that was, whenever you have a lot of runoff, it fills the lake with nutrients — phosphorous, nitrogen,” Patterson said. “And, then, the algae feed off of that … with a lot of rainfall, we’ve had a lot of algae bloom.”

Patterson said the process of “changing carbon out” of the lake occurs every two years. However, the process didn’t seem to be working and needed to be changed after a year.

“It expired before the two years, so it kind of nipped us in the rear, and then we had severe taste and odor issues,” Patterson said.

Disinfecting

The water department “feeds” chlorine dioxide as a disinfectant at West Lake, Patterson said.

The department also monitors the byproduct of the disinfectant. Filters help remove the byproduct.

Patterson said the carbon was “worn out” and it couldn’t “feed enough chemical” to take care of the taste and odor of the water.

In July, the water department implemented new carbon to help treat the water supply.

“We thought we were going to sail through the winter, and everything was going to be good,” Patterson said. “Well, then we hit record temperatures the last week, week and a-half. So, once again, our algae in the lake is extremely not normal with the amount that we have.”

Finding a solution

Chlorine dioxide is still the water department’s primary disinfectant, but the department is maxed out on the chemicals that help treat the water’s taste and odor.

Another part of the problem, Patterson said, is there are different strains of algae not usually seen at the lake.

Patterson said the department is working with its engineer to find a solution. There are various solutions, including building a basin below the plant to help with additional treatment.

“It all boils down to contact time with the chemical, and we just don’t have a lot,” Patterson said.